In a recent DT:101 posting, I went over how you can use Full Server Fail Over (FSFO) technology to safely protect Microsoft Exchange Servers, even though this isn’t our best practice here at Double-Take Software. This prompted quite a few questions about the other applications that are covered using our Application Failover Manager (usually called DTAM) technology. Both types of failover are included in Double-Take Availability, and are both fully supported by Double-Take Software for just about anything running on a Windows Server platform. So, here’s a brief run-down of where our best practices lie for the applications that DTAM technology supports:
SQL Server: We recommend DTAM technology for SQL Servers that are running Microsoft SQL Server 2000 and up, and that are not running other software on the same machine. Where 3rd-Party SQL-specific tools (like a database front-end system) are running on the same server as SQL, then Full Server Fail Over (FSFO) technologies are a better bet.
Best Practice Recommendation: DTAM (Application Failover Manager)
File Servers: DTAM is the preferred solution if the file servers are not running additional application on the same device. However, if there are many applications running on the server, or if the primary function of the server is to run as a Print Queue server, then FSFO is an easier solution to use.
Best Practice Recommendation: DTAM (Application Failover Manager)
Blackberry Enterprise Server (BES): FSFO offers some compelling features for a single-instance system such as BES. The SRP security identifier can only be in-use on one server at a time, and therefore having it installed on the target device can lead to accidental license violations. This causes RIM to lock both devices out of the network, bringing your mobile workforce to a screeching halt. DTAM solutions are available for BES, but are typically used to assist in providing high availability paired with off-site disaster recovery.
Best Practice Recommendation: Full Server Fail Over
SharePoint Services: Single-server SharePoint should leverage FSFO technology to allow for changes to configurations and other system-level changes to be replicated automatically to a target device. However, to provide both local high availability and remote disaster recovery, you will use both FSFO and DTAM, so we make sure SharePoint is one of our DTAM wizards.
Best Practice Recommendation: Full Server Fail Over
Always remember that you can choose either form of failover technology (DTAM vs. FSFO) for any server in your environment. These best practices simply offer guidance on what we’ve seen work best across the majority of our clients. When in doubt, give Technical Support a ring (http://www.doubletake.com/support) and run the solution by them for further guidance.
Filed under: Best Practices, DT 101, Exchange, SQL Server, SharePoint, Workload Availability
